The generation of the mesh is not made
directly by TELEMAC. Therefore we have used a well adapted mesh builder
called MATISSE. The first step is the generation of
the bathymetry of the problem. To do this we ask Matisse to load a folder
where are the different coordinates of the points.This bathymetry was given
to simplify the study. This is a very simple bathymetry only composed by
only two bathymetry lines (one for sides and the other one for the middle
of the river):

Bathymetry of the study.

The software RUBENS permit the visualisation
of the bathymetry:

The mesh

The second step is the meshing of the geometry.
We decided to refine the mesh near the middle of the river wish is the
deepest zone of the problem. The mesh we have generated, is composed by
about 5000 nodes. The two next pictures show two zooms of the mesh, one
in the top of the first river and the other in the confluence zone:

Zoom of the mesh at the top of the river

Zoom of the mesh in the confluence zone

Boundary conditions

The last step is the generation of boundary
conditions zones. Here the problem is simple with two inlet, one outlet
and three zones for side conditions: